Adding support for an array of links to the waveform record.

[jerzyjamroz]

After evaluating the use of tableRecord with an array of links, this idea came up.

The idea is to allow a waveform input to be defined as a list of PV links, for example:

record(waveform, "P:WAV:TEST") { 
  field(DTYP, "Soft Channel") 
  field(INP, {link: ["P:VAR1", "P:VAR2", "P:VAR3"]}) 
  field(FTVL, "DOUBLE") field(NELM, "10") 
}

One use case for this is tableRecord. For example, optional column data could be collected from several independent PVs into one waveform and then connected to an optional column:

field(CO02INP, "P:WAV:TEST")
field(CO02TYPE, "DOUBLE")

In general, it would provide a simple way to collect values from multiple scalar PVs into a single array PV.

Example proposal:
https://github.com/jerzyjamroz/tableRecord/blob/waveformlink/exampleApp/Db/waveformlink.db